xref: /openbmc/linux/arch/s390/Kconfig (revision 9e6bfd42b14b45737cae8bc84c759f1874949b8b)
1# SPDX-License-Identifier: GPL-2.0
2config MMU
3	def_bool y
4
5config CPU_BIG_ENDIAN
6	def_bool y
7
8config LOCKDEP_SUPPORT
9	def_bool y
10
11config STACKTRACE_SUPPORT
12	def_bool y
13
14config ARCH_HAS_ILOG2_U32
15	def_bool n
16
17config ARCH_HAS_ILOG2_U64
18	def_bool n
19
20config GENERIC_HWEIGHT
21	def_bool y
22
23config GENERIC_BUG
24	def_bool y if BUG
25
26config GENERIC_BUG_RELATIVE_POINTERS
27	def_bool y
28
29config GENERIC_CSUM
30	bool
31	default y if KASAN
32
33config GENERIC_LOCKBREAK
34	def_bool y if PREEMPTION
35
36config PGSTE
37	def_bool y if KVM
38
39config AUDIT_ARCH
40	def_bool y
41
42config NO_IOPORT_MAP
43	def_bool y
44
45config PCI_QUIRKS
46	def_bool n
47
48config ARCH_SUPPORTS_UPROBES
49	def_bool y
50
51config KASAN_SHADOW_OFFSET
52	hex
53	depends on KASAN
54	default 0x1C000000000000
55
56config S390
57	def_bool y
58	#
59	# Note: keep this list sorted alphabetically
60	#
61	imply IMA_SECURE_AND_OR_TRUSTED_BOOT
62	select ALTERNATE_USER_ADDRESS_SPACE
63	select ARCH_32BIT_USTAT_F_TINODE
64	select ARCH_BINFMT_ELF_STATE
65	select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
66	select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM
67	select ARCH_ENABLE_MEMORY_HOTREMOVE
68	select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2
69	select ARCH_HAS_CURRENT_STACK_POINTER
70	select ARCH_HAS_DEBUG_VM_PGTABLE
71	select ARCH_HAS_DEBUG_WX
72	select ARCH_HAS_DEVMEM_IS_ALLOWED
73	select ARCH_HAS_ELF_RANDOMIZE
74	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
75	select ARCH_HAS_FORTIFY_SOURCE
76	select ARCH_HAS_GCOV_PROFILE_ALL
77	select ARCH_HAS_GIGANTIC_PAGE
78	select ARCH_HAS_KCOV
79	select ARCH_HAS_MEM_ENCRYPT
80	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
81	select ARCH_HAS_PTE_SPECIAL
82	select ARCH_HAS_SCALED_CPUTIME
83	select ARCH_HAS_SET_MEMORY
84	select ARCH_HAS_STRICT_KERNEL_RWX
85	select ARCH_HAS_STRICT_MODULE_RWX
86	select ARCH_HAS_SYSCALL_WRAPPER
87	select ARCH_HAS_UBSAN_SANITIZE_ALL
88	select ARCH_HAS_VDSO_DATA
89	select ARCH_HAVE_NMI_SAFE_CMPXCHG
90	select ARCH_INLINE_READ_LOCK
91	select ARCH_INLINE_READ_LOCK_BH
92	select ARCH_INLINE_READ_LOCK_IRQ
93	select ARCH_INLINE_READ_LOCK_IRQSAVE
94	select ARCH_INLINE_READ_TRYLOCK
95	select ARCH_INLINE_READ_UNLOCK
96	select ARCH_INLINE_READ_UNLOCK_BH
97	select ARCH_INLINE_READ_UNLOCK_IRQ
98	select ARCH_INLINE_READ_UNLOCK_IRQRESTORE
99	select ARCH_INLINE_SPIN_LOCK
100	select ARCH_INLINE_SPIN_LOCK_BH
101	select ARCH_INLINE_SPIN_LOCK_IRQ
102	select ARCH_INLINE_SPIN_LOCK_IRQSAVE
103	select ARCH_INLINE_SPIN_TRYLOCK
104	select ARCH_INLINE_SPIN_TRYLOCK_BH
105	select ARCH_INLINE_SPIN_UNLOCK
106	select ARCH_INLINE_SPIN_UNLOCK_BH
107	select ARCH_INLINE_SPIN_UNLOCK_IRQ
108	select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE
109	select ARCH_INLINE_WRITE_LOCK
110	select ARCH_INLINE_WRITE_LOCK_BH
111	select ARCH_INLINE_WRITE_LOCK_IRQ
112	select ARCH_INLINE_WRITE_LOCK_IRQSAVE
113	select ARCH_INLINE_WRITE_TRYLOCK
114	select ARCH_INLINE_WRITE_UNLOCK
115	select ARCH_INLINE_WRITE_UNLOCK_BH
116	select ARCH_INLINE_WRITE_UNLOCK_IRQ
117	select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE
118	select ARCH_STACKWALK
119	select ARCH_SUPPORTS_ATOMIC_RMW
120	select ARCH_SUPPORTS_DEBUG_PAGEALLOC
121	select ARCH_SUPPORTS_HUGETLBFS
122	select ARCH_SUPPORTS_NUMA_BALANCING
123	select ARCH_USE_BUILTIN_BSWAP
124	select ARCH_USE_CMPXCHG_LOCKREF
125	select ARCH_WANTS_DYNAMIC_TASK_STRUCT
126	select ARCH_WANTS_NO_INSTR
127	select ARCH_WANT_DEFAULT_BPF_JIT
128	select ARCH_WANT_IPC_PARSE_VERSION
129	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
130	select BUILDTIME_TABLE_SORT
131	select CLONE_BACKWARDS2
132	select DMA_OPS if PCI
133	select DYNAMIC_FTRACE if FUNCTION_TRACER
134	select GCC12_NO_ARRAY_BOUNDS
135	select GENERIC_ALLOCATOR
136	select GENERIC_CPU_AUTOPROBE
137	select GENERIC_CPU_VULNERABILITIES
138	select GENERIC_ENTRY
139	select GENERIC_GETTIMEOFDAY
140	select GENERIC_PTDUMP
141	select GENERIC_SMP_IDLE_THREAD
142	select GENERIC_TIME_VSYSCALL
143	select GENERIC_VDSO_TIME_NS
144	select HAVE_ALIGNED_STRUCT_PAGE if SLUB
145	select HAVE_ARCH_AUDITSYSCALL
146	select HAVE_ARCH_JUMP_LABEL
147	select HAVE_ARCH_JUMP_LABEL_RELATIVE
148	select HAVE_ARCH_KASAN
149	select HAVE_ARCH_KASAN_VMALLOC
150	select HAVE_ARCH_KCSAN
151	select HAVE_ARCH_KFENCE
152	select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
153	select HAVE_ARCH_SECCOMP_FILTER
154	select HAVE_ARCH_SOFT_DIRTY
155	select HAVE_ARCH_TRACEHOOK
156	select HAVE_ARCH_TRANSPARENT_HUGEPAGE
157	select HAVE_ARCH_VMAP_STACK
158	select HAVE_ASM_MODVERSIONS
159	select HAVE_CMPXCHG_DOUBLE
160	select HAVE_CMPXCHG_LOCAL
161	select HAVE_DEBUG_KMEMLEAK
162	select HAVE_DMA_CONTIGUOUS
163	select HAVE_DYNAMIC_FTRACE
164	select HAVE_DYNAMIC_FTRACE_WITH_ARGS
165	select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
166	select HAVE_DYNAMIC_FTRACE_WITH_REGS
167	select HAVE_EBPF_JIT if HAVE_MARCH_Z196_FEATURES
168	select HAVE_EFFICIENT_UNALIGNED_ACCESS
169	select HAVE_FAST_GUP
170	select HAVE_FENTRY
171	select HAVE_FTRACE_MCOUNT_RECORD
172	select HAVE_FUNCTION_ARG_ACCESS_API
173	select HAVE_FUNCTION_ERROR_INJECTION
174	select HAVE_FUNCTION_GRAPH_TRACER
175	select HAVE_FUNCTION_TRACER
176	select HAVE_GCC_PLUGINS
177	select HAVE_GENERIC_VDSO
178	select HAVE_IOREMAP_PROT if PCI
179	select HAVE_KERNEL_BZIP2
180	select HAVE_KERNEL_GZIP
181	select HAVE_KERNEL_LZ4
182	select HAVE_KERNEL_LZMA
183	select HAVE_KERNEL_LZO
184	select HAVE_KERNEL_UNCOMPRESSED
185	select HAVE_KERNEL_XZ
186	select HAVE_KERNEL_ZSTD
187	select HAVE_KPROBES
188	select HAVE_KPROBES_ON_FTRACE
189	select HAVE_KRETPROBES
190	select HAVE_RETHOOK
191	select HAVE_KVM
192	select HAVE_LIVEPATCH
193	select HAVE_MEMBLOCK_PHYS_MAP
194	select HAVE_MOD_ARCH_SPECIFIC
195	select HAVE_NMI
196	select HAVE_NOP_MCOUNT
197	select HAVE_PCI
198	select HAVE_PERF_EVENTS
199	select HAVE_PERF_REGS
200	select HAVE_PERF_USER_STACK_DUMP
201	select HAVE_REGS_AND_STACK_ACCESS_API
202	select HAVE_RELIABLE_STACKTRACE
203	select HAVE_RSEQ
204	select HAVE_SAMPLE_FTRACE_DIRECT
205	select HAVE_SAMPLE_FTRACE_DIRECT_MULTI
206	select HAVE_SETUP_PER_CPU_AREA
207	select HAVE_SOFTIRQ_ON_OWN_STACK
208	select HAVE_SYSCALL_TRACEPOINTS
209	select HAVE_VIRT_CPU_ACCOUNTING
210	select HAVE_VIRT_CPU_ACCOUNTING_IDLE
211	select IOMMU_HELPER		if PCI
212	select IOMMU_SUPPORT		if PCI
213	select MMU_GATHER_NO_GATHER
214	select MMU_GATHER_RCU_TABLE_FREE
215	select MMU_GATHER_MERGE_VMAS
216	select MODULES_USE_ELF_RELA
217	select NEED_DMA_MAP_STATE	if PCI
218	select NEED_PER_CPU_EMBED_FIRST_CHUNK
219	select NEED_SG_DMA_LENGTH	if PCI
220	select OLD_SIGACTION
221	select OLD_SIGSUSPEND3
222	select PCI_DOMAINS		if PCI
223	select PCI_MSI			if PCI
224	select PCI_MSI_ARCH_FALLBACKS	if PCI_MSI
225	select SPARSE_IRQ
226	select SWIOTLB
227	select SYSCTL_EXCEPTION_TRACE
228	select THREAD_INFO_IN_TASK
229	select TRACE_IRQFLAGS_SUPPORT
230	select TTY
231	select VIRT_CPU_ACCOUNTING
232	select ZONE_DMA
233	# Note: keep the above list sorted alphabetically
234
235config SCHED_OMIT_FRAME_POINTER
236	def_bool y
237
238config PGTABLE_LEVELS
239	int
240	default 5
241
242source "kernel/livepatch/Kconfig"
243
244menu "Processor type and features"
245
246config HAVE_MARCH_Z10_FEATURES
247	def_bool n
248
249config HAVE_MARCH_Z196_FEATURES
250	def_bool n
251	select HAVE_MARCH_Z10_FEATURES
252
253config HAVE_MARCH_ZEC12_FEATURES
254	def_bool n
255	select HAVE_MARCH_Z196_FEATURES
256
257config HAVE_MARCH_Z13_FEATURES
258	def_bool n
259	select HAVE_MARCH_ZEC12_FEATURES
260
261config HAVE_MARCH_Z14_FEATURES
262	def_bool n
263	select HAVE_MARCH_Z13_FEATURES
264
265config HAVE_MARCH_Z15_FEATURES
266	def_bool n
267	select HAVE_MARCH_Z14_FEATURES
268
269config HAVE_MARCH_Z16_FEATURES
270	def_bool n
271	select HAVE_MARCH_Z15_FEATURES
272
273choice
274	prompt "Processor type"
275	default MARCH_Z196
276
277config MARCH_Z10
278	bool "IBM System z10"
279	select HAVE_MARCH_Z10_FEATURES
280	depends on $(cc-option,-march=z10)
281	help
282	  Select this to enable optimizations for IBM System z10 (2097 and 2098
283	  series). This is the oldest machine generation currently supported.
284
285config MARCH_Z196
286	bool "IBM zEnterprise 114 and 196"
287	select HAVE_MARCH_Z196_FEATURES
288	depends on $(cc-option,-march=z196)
289	help
290	  Select this to enable optimizations for IBM zEnterprise 114 and 196
291	  (2818 and 2817 series). The kernel will be slightly faster but will
292	  not work on older machines.
293
294config MARCH_ZEC12
295	bool "IBM zBC12 and zEC12"
296	select HAVE_MARCH_ZEC12_FEATURES
297	depends on $(cc-option,-march=zEC12)
298	help
299	  Select this to enable optimizations for IBM zBC12 and zEC12 (2828 and
300	  2827 series). The kernel will be slightly faster but will not work on
301	  older machines.
302
303config MARCH_Z13
304	bool "IBM z13s and z13"
305	select HAVE_MARCH_Z13_FEATURES
306	depends on $(cc-option,-march=z13)
307	help
308	  Select this to enable optimizations for IBM z13s and z13 (2965 and
309	  2964 series). The kernel will be slightly faster but will not work on
310	  older machines.
311
312config MARCH_Z14
313	bool "IBM z14 ZR1 and z14"
314	select HAVE_MARCH_Z14_FEATURES
315	depends on $(cc-option,-march=z14)
316	help
317	  Select this to enable optimizations for IBM z14 ZR1 and z14 (3907
318	  and 3906 series). The kernel will be slightly faster but will not
319	  work on older machines.
320
321config MARCH_Z15
322	bool "IBM z15"
323	select HAVE_MARCH_Z15_FEATURES
324	depends on $(cc-option,-march=z15)
325	help
326	  Select this to enable optimizations for IBM z15 (8562
327	  and 8561 series). The kernel will be slightly faster but will not
328	  work on older machines.
329
330config MARCH_Z16
331	bool "IBM z16"
332	select HAVE_MARCH_Z16_FEATURES
333	depends on $(cc-option,-march=z16)
334	help
335	  Select this to enable optimizations for IBM z16 (3931 and
336	  3932 series).
337
338endchoice
339
340config MARCH_Z10_TUNE
341	def_bool TUNE_Z10 || MARCH_Z10 && TUNE_DEFAULT
342
343config MARCH_Z196_TUNE
344	def_bool TUNE_Z196 || MARCH_Z196 && TUNE_DEFAULT
345
346config MARCH_ZEC12_TUNE
347	def_bool TUNE_ZEC12 || MARCH_ZEC12 && TUNE_DEFAULT
348
349config MARCH_Z13_TUNE
350	def_bool TUNE_Z13 || MARCH_Z13 && TUNE_DEFAULT
351
352config MARCH_Z14_TUNE
353	def_bool TUNE_Z14 || MARCH_Z14 && TUNE_DEFAULT
354
355config MARCH_Z15_TUNE
356	def_bool TUNE_Z15 || MARCH_Z15 && TUNE_DEFAULT
357
358config MARCH_Z16_TUNE
359	def_bool TUNE_Z16 || MARCH_Z16 && TUNE_DEFAULT
360
361choice
362	prompt "Tune code generation"
363	default TUNE_DEFAULT
364	help
365	  Cause the compiler to tune (-mtune) the generated code for a machine.
366	  This will make the code run faster on the selected machine but
367	  somewhat slower on other machines.
368	  This option only changes how the compiler emits instructions, not the
369	  selection of instructions itself, so the resulting kernel will run on
370	  all other machines.
371
372config TUNE_DEFAULT
373	bool "Default"
374	help
375	  Tune the generated code for the target processor for which the kernel
376	  will be compiled.
377
378config TUNE_Z10
379	bool "IBM System z10"
380
381config TUNE_Z196
382	bool "IBM zEnterprise 114 and 196"
383	depends on $(cc-option,-mtune=z196)
384
385config TUNE_ZEC12
386	bool "IBM zBC12 and zEC12"
387	depends on $(cc-option,-mtune=zEC12)
388
389config TUNE_Z13
390	bool "IBM z13s and z13"
391	depends on $(cc-option,-mtune=z13)
392
393config TUNE_Z14
394	bool "IBM z14 ZR1 and z14"
395	depends on $(cc-option,-mtune=z14)
396
397config TUNE_Z15
398	bool "IBM z15"
399	depends on $(cc-option,-mtune=z15)
400
401config TUNE_Z16
402	bool "IBM z16"
403	depends on $(cc-option,-mtune=z16)
404
405endchoice
406
407config 64BIT
408	def_bool y
409
410config COMMAND_LINE_SIZE
411	int "Maximum size of kernel command line"
412	default 4096
413	range 896 1048576
414	help
415	  This allows you to specify the maximum length of the kernel command
416	  line.
417
418config COMPAT
419	def_bool y
420	prompt "Kernel support for 31 bit emulation"
421	select ARCH_WANT_OLD_COMPAT_IPC
422	select COMPAT_OLD_SIGACTION
423	select HAVE_UID16
424	depends on MULTIUSER
425	depends on !CC_IS_CLANG
426	help
427	  Select this option if you want to enable your system kernel to
428	  handle system-calls from ELF binaries for 31 bit ESA.  This option
429	  (and some other stuff like libraries and such) is needed for
430	  executing 31 bit applications.  It is safe to say "Y".
431
432config SMP
433	def_bool y
434
435config NR_CPUS
436	int "Maximum number of CPUs (2-512)"
437	range 2 512
438	default "64"
439	help
440	  This allows you to specify the maximum number of CPUs which this
441	  kernel will support. The maximum supported value is 512 and the
442	  minimum value which makes sense is 2.
443
444	  This is purely to save memory - each supported CPU adds
445	  approximately sixteen kilobytes to the kernel image.
446
447config HOTPLUG_CPU
448	def_bool y
449
450config NUMA
451	bool "NUMA support"
452	depends on SCHED_TOPOLOGY
453	default n
454	help
455	  Enable NUMA support
456
457	  This option adds NUMA support to the kernel.
458
459config NODES_SHIFT
460	int
461	depends on NUMA
462	default "1"
463
464config SCHED_SMT
465	def_bool n
466
467config SCHED_MC
468	def_bool n
469
470config SCHED_BOOK
471	def_bool n
472
473config SCHED_DRAWER
474	def_bool n
475
476config SCHED_TOPOLOGY
477	def_bool y
478	prompt "Topology scheduler support"
479	select SCHED_SMT
480	select SCHED_MC
481	select SCHED_BOOK
482	select SCHED_DRAWER
483	help
484	  Topology scheduler support improves the CPU scheduler's decision
485	  making when dealing with machines that have multi-threading,
486	  multiple cores or multiple books.
487
488source "kernel/Kconfig.hz"
489
490config KEXEC
491	def_bool y
492	select KEXEC_CORE
493
494config KEXEC_FILE
495	bool "kexec file based system call"
496	select KEXEC_CORE
497	depends on CRYPTO
498	depends on CRYPTO_SHA256
499	depends on CRYPTO_SHA256_S390
500	help
501	  Enable the kexec file based system call. In contrast to the normal
502	  kexec system call this system call takes file descriptors for the
503	  kernel and initramfs as arguments.
504
505config ARCH_HAS_KEXEC_PURGATORY
506	def_bool y
507	depends on KEXEC_FILE
508
509config KEXEC_SIG
510	bool "Verify kernel signature during kexec_file_load() syscall"
511	depends on KEXEC_FILE && MODULE_SIG_FORMAT
512	help
513	  This option makes kernel signature verification mandatory for
514	  the kexec_file_load() syscall.
515
516	  In addition to that option, you need to enable signature
517	  verification for the corresponding kernel image type being
518	  loaded in order for this to work.
519
520config KERNEL_NOBP
521	def_bool n
522	prompt "Enable modified branch prediction for the kernel by default"
523	help
524	  If this option is selected the kernel will switch to a modified
525	  branch prediction mode if the firmware interface is available.
526	  The modified branch prediction mode improves the behaviour in
527	  regard to speculative execution.
528
529	  With the option enabled the kernel parameter "nobp=0" or "nospec"
530	  can be used to run the kernel in the normal branch prediction mode.
531
532	  With the option disabled the modified branch prediction mode is
533	  enabled with the "nobp=1" kernel parameter.
534
535	  If unsure, say N.
536
537config EXPOLINE
538	def_bool n
539	depends on $(cc-option,-mindirect-branch=thunk)
540	prompt "Avoid speculative indirect branches in the kernel"
541	help
542	  Compile the kernel with the expoline compiler options to guard
543	  against kernel-to-user data leaks by avoiding speculative indirect
544	  branches.
545	  Requires a compiler with -mindirect-branch=thunk support for full
546	  protection. The kernel may run slower.
547
548	  If unsure, say N.
549
550config EXPOLINE_EXTERN
551	def_bool n
552	depends on EXPOLINE
553	depends on CC_IS_GCC && GCC_VERSION >= 110200
554	depends on $(success,$(srctree)/arch/s390/tools/gcc-thunk-extern.sh $(CC))
555	prompt "Generate expolines as extern functions."
556	help
557	  This option is required for some tooling like kpatch. The kernel is
558	  compiled with -mindirect-branch=thunk-extern and requires a newer
559	  compiler.
560
561	  If unsure, say N.
562
563choice
564	prompt "Expoline default"
565	depends on EXPOLINE
566	default EXPOLINE_FULL
567
568config EXPOLINE_OFF
569	bool "spectre_v2=off"
570
571config EXPOLINE_AUTO
572	bool "spectre_v2=auto"
573
574config EXPOLINE_FULL
575	bool "spectre_v2=on"
576
577endchoice
578
579config RELOCATABLE
580	def_bool y
581	help
582	  This builds a kernel image that retains relocation information
583	  so it can be loaded at an arbitrary address.
584	  The kernel is linked as a position-independent executable (PIE)
585	  and contains dynamic relocations which are processed early in the
586	  bootup process.
587	  The relocations make the kernel image about 15% larger (compressed
588	  10%), but are discarded at runtime.
589	  Note: this option exists only for documentation purposes, please do
590	  not remove it.
591
592config RANDOMIZE_BASE
593	bool "Randomize the address of the kernel image (KASLR)"
594	default y
595	help
596	  In support of Kernel Address Space Layout Randomization (KASLR),
597	  this randomizes the address at which the kernel image is loaded,
598	  as a security feature that deters exploit attempts relying on
599	  knowledge of the location of kernel internals.
600
601endmenu
602
603menu "Memory setup"
604
605config ARCH_SPARSEMEM_ENABLE
606	def_bool y
607	select SPARSEMEM_VMEMMAP_ENABLE
608	select SPARSEMEM_VMEMMAP
609
610config ARCH_SPARSEMEM_DEFAULT
611	def_bool y
612
613config MAX_PHYSMEM_BITS
614	int "Maximum size of supported physical memory in bits (42-53)"
615	range 42 53
616	default "46"
617	help
618	  This option specifies the maximum supported size of physical memory
619	  in bits. Supported is any size between 2^42 (4TB) and 2^53 (8PB).
620	  Increasing the number of bits also increases the kernel image size.
621	  By default 46 bits (64TB) are supported.
622
623config CHECK_STACK
624	def_bool y
625	depends on !VMAP_STACK
626	prompt "Detect kernel stack overflow"
627	help
628	  This option enables the compiler option -mstack-guard and
629	  -mstack-size if they are available. If the compiler supports them
630	  it will emit additional code to each function prolog to trigger
631	  an illegal operation if the kernel stack is about to overflow.
632
633	  Say N if you are unsure.
634
635config STACK_GUARD
636	int "Size of the guard area (128-1024)"
637	range 128 1024
638	depends on CHECK_STACK
639	default "256"
640	help
641	  This allows you to specify the size of the guard area at the lower
642	  end of the kernel stack. If the kernel stack points into the guard
643	  area on function entry an illegal operation is triggered. The size
644	  needs to be a power of 2. Please keep in mind that the size of an
645	  interrupt frame is 184 bytes for 31 bit and 328 bytes on 64 bit.
646	  The minimum size for the stack guard should be 256 for 31 bit and
647	  512 for 64 bit.
648
649endmenu
650
651menu "I/O subsystem"
652
653config QDIO
654	def_tristate y
655	prompt "QDIO support"
656	help
657	  This driver provides the Queued Direct I/O base support for
658	  IBM System z.
659
660	  To compile this driver as a module, choose M here: the
661	  module will be called qdio.
662
663	  If unsure, say Y.
664
665if PCI
666
667config PCI_NR_FUNCTIONS
668	int "Maximum number of PCI functions (1-4096)"
669	range 1 4096
670	default "512"
671	help
672	  This allows you to specify the maximum number of PCI functions which
673	  this kernel will support.
674
675endif # PCI
676
677config HAS_IOMEM
678	def_bool PCI
679
680config CHSC_SCH
681	def_tristate m
682	prompt "Support for CHSC subchannels"
683	help
684	  This driver allows usage of CHSC subchannels. A CHSC subchannel
685	  is usually present on LPAR only.
686	  The driver creates a device /dev/chsc, which may be used to
687	  obtain I/O configuration information about the machine and
688	  to issue asynchronous chsc commands (DANGEROUS).
689	  You will usually only want to use this interface on a special
690	  LPAR designated for system management.
691
692	  To compile this driver as a module, choose M here: the
693	  module will be called chsc_sch.
694
695	  If unsure, say N.
696
697config SCM_BUS
698	def_bool y
699	prompt "SCM bus driver"
700	help
701	  Bus driver for Storage Class Memory.
702
703config EADM_SCH
704	def_tristate m
705	prompt "Support for EADM subchannels"
706	depends on SCM_BUS
707	help
708	  This driver allows usage of EADM subchannels. EADM subchannels act
709	  as a communication vehicle for SCM increments.
710
711	  To compile this driver as a module, choose M here: the
712	  module will be called eadm_sch.
713
714config VFIO_CCW
715	def_tristate n
716	prompt "Support for VFIO-CCW subchannels"
717	depends on S390_CCW_IOMMU && VFIO_MDEV
718	help
719	  This driver allows usage of I/O subchannels via VFIO-CCW.
720
721	  To compile this driver as a module, choose M here: the
722	  module will be called vfio_ccw.
723
724config VFIO_AP
725	def_tristate n
726	prompt "VFIO support for AP devices"
727	depends on S390_AP_IOMMU && VFIO_MDEV && KVM
728	depends on ZCRYPT
729	help
730	  This driver grants access to Adjunct Processor (AP) devices
731	  via the VFIO mediated device interface.
732
733	  To compile this driver as a module, choose M here: the module
734	  will be called vfio_ap.
735
736endmenu
737
738menu "Dump support"
739
740config CRASH_DUMP
741	bool "kernel crash dumps"
742	select KEXEC
743	help
744	  Generate crash dump after being started by kexec.
745	  Crash dump kernels are loaded in the main kernel with kexec-tools
746	  into a specially reserved region and then later executed after
747	  a crash by kdump/kexec.
748	  Refer to <file:Documentation/s390/zfcpdump.rst> for more details on this.
749	  This option also enables s390 zfcpdump.
750	  See also <file:Documentation/s390/zfcpdump.rst>
751
752endmenu
753
754config CCW
755	def_bool y
756
757config HAVE_PNETID
758	tristate
759	default (SMC || CCWGROUP)
760
761menu "Virtualization"
762
763config PROTECTED_VIRTUALIZATION_GUEST
764	def_bool n
765	prompt "Protected virtualization guest support"
766	help
767	  Select this option, if you want to be able to run this
768	  kernel as a protected virtualization KVM guest.
769	  Protected virtualization capable machines have a mini hypervisor
770	  located at machine level (an ultravisor). With help of the
771	  Ultravisor, KVM will be able to run "protected" VMs, special
772	  VMs whose memory and management data are unavailable to KVM.
773
774config PFAULT
775	def_bool y
776	prompt "Pseudo page fault support"
777	help
778	  Select this option, if you want to use PFAULT pseudo page fault
779	  handling under VM. If running native or in LPAR, this option
780	  has no effect. If your VM does not support PFAULT, PAGEEX
781	  pseudo page fault handling will be used.
782	  Note that VM 4.2 supports PFAULT but has a bug in its
783	  implementation that causes some problems.
784	  Everybody who wants to run Linux under VM != VM4.2 should select
785	  this option.
786
787config CMM
788	def_tristate n
789	prompt "Cooperative memory management"
790	help
791	  Select this option, if you want to enable the kernel interface
792	  to reduce the memory size of the system. This is accomplished
793	  by allocating pages of memory and put them "on hold". This only
794	  makes sense for a system running under VM where the unused pages
795	  will be reused by VM for other guest systems. The interface
796	  allows an external monitor to balance memory of many systems.
797	  Everybody who wants to run Linux under VM should select this
798	  option.
799
800config CMM_IUCV
801	def_bool y
802	prompt "IUCV special message interface to cooperative memory management"
803	depends on CMM && (SMSGIUCV=y || CMM=SMSGIUCV)
804	help
805	  Select this option to enable the special message interface to
806	  the cooperative memory management.
807
808config APPLDATA_BASE
809	def_bool n
810	prompt "Linux - VM Monitor Stream, base infrastructure"
811	depends on PROC_SYSCTL
812	help
813	  This provides a kernel interface for creating and updating z/VM APPLDATA
814	  monitor records. The monitor records are updated at certain time
815	  intervals, once the timer is started.
816	  Writing 1 or 0 to /proc/appldata/timer starts(1) or stops(0) the timer,
817	  i.e. enables or disables monitoring on the Linux side.
818	  A custom interval value (in seconds) can be written to
819	  /proc/appldata/interval.
820
821	  Defaults are 60 seconds interval and timer off.
822	  The /proc entries can also be read from, showing the current settings.
823
824config APPLDATA_MEM
825	def_tristate m
826	prompt "Monitor memory management statistics"
827	depends on APPLDATA_BASE && VM_EVENT_COUNTERS
828	help
829	  This provides memory management related data to the Linux - VM Monitor
830	  Stream, like paging/swapping rate, memory utilisation, etc.
831	  Writing 1 or 0 to /proc/appldata/memory creates(1) or removes(0) a z/VM
832	  APPLDATA monitor record, i.e. enables or disables monitoring this record
833	  on the z/VM side.
834
835	  Default is disabled.
836	  The /proc entry can also be read from, showing the current settings.
837
838	  This can also be compiled as a module, which will be called
839	  appldata_mem.o.
840
841config APPLDATA_OS
842	def_tristate m
843	prompt "Monitor OS statistics"
844	depends on APPLDATA_BASE
845	help
846	  This provides OS related data to the Linux - VM Monitor Stream, like
847	  CPU utilisation, etc.
848	  Writing 1 or 0 to /proc/appldata/os creates(1) or removes(0) a z/VM
849	  APPLDATA monitor record, i.e. enables or disables monitoring this record
850	  on the z/VM side.
851
852	  Default is disabled.
853	  This can also be compiled as a module, which will be called
854	  appldata_os.o.
855
856config APPLDATA_NET_SUM
857	def_tristate m
858	prompt "Monitor overall network statistics"
859	depends on APPLDATA_BASE && NET
860	help
861	  This provides network related data to the Linux - VM Monitor Stream,
862	  currently there is only a total sum of network I/O statistics, no
863	  per-interface data.
864	  Writing 1 or 0 to /proc/appldata/net_sum creates(1) or removes(0) a z/VM
865	  APPLDATA monitor record, i.e. enables or disables monitoring this record
866	  on the z/VM side.
867
868	  Default is disabled.
869	  This can also be compiled as a module, which will be called
870	  appldata_net_sum.o.
871
872config S390_HYPFS_FS
873	def_bool y
874	prompt "s390 hypervisor file system support"
875	select SYS_HYPERVISOR
876	help
877	  This is a virtual file system intended to provide accounting
878	  information in an s390 hypervisor environment.
879
880source "arch/s390/kvm/Kconfig"
881
882config S390_GUEST
883	def_bool y
884	prompt "s390 support for virtio devices"
885	select TTY
886	select VIRTUALIZATION
887	select VIRTIO
888	help
889	  Enabling this option adds support for virtio based paravirtual device
890	  drivers on s390.
891
892	  Select this option if you want to run the kernel as a guest under
893	  the KVM hypervisor.
894
895endmenu
896
897config S390_MODULES_SANITY_TEST_HELPERS
898	def_bool n
899
900menu "Selftests"
901
902config S390_UNWIND_SELFTEST
903	def_tristate n
904	depends on KUNIT
905	default KUNIT_ALL_TESTS
906	prompt "Test unwind functions"
907	help
908	  This option enables s390 specific stack unwinder testing kernel
909	  module. This option is not useful for distributions or general
910	  kernels, but only for kernel developers working on architecture code.
911
912	  Say N if you are unsure.
913
914config S390_KPROBES_SANITY_TEST
915	def_tristate n
916	prompt "Enable s390 specific kprobes tests"
917	depends on KPROBES
918	depends on KUNIT
919	help
920	  This option enables an s390 specific kprobes test module. This option
921	  is not useful for distributions or general kernels, but only for kernel
922	  developers working on architecture code.
923
924	  Say N if you are unsure.
925
926config S390_MODULES_SANITY_TEST
927	def_tristate n
928	depends on KUNIT
929	default KUNIT_ALL_TESTS
930	prompt "Enable s390 specific modules tests"
931	select S390_MODULES_SANITY_TEST_HELPERS
932	help
933	  This option enables an s390 specific modules test. This option is
934	  not useful for distributions or general kernels, but only for
935	  kernel developers working on architecture code.
936
937	  Say N if you are unsure.
938endmenu
939